The subject invention relates to an introducer needle assembly for use with a catheter, where the introducer needle assembly includes a tethered needle shield that will safely shield the sharp distal tip of the introducer needle after the needle has been used to insert the catheter into a patient.
Catheters, particularly intravenous (IV) catheters, are used for infusing fluid, such as normal saline solution, various medicaments and total parenteral nutrition, into a patient or withdrawing blood from a patient. Peripheral IV catheters tend to be relatively short, and are on the order of about one and one-half inches in length. The most common type of IV catheter is an over the needle peripheral IV catheter. As its name implies, an over the needle catheter is mounted over an introducer needle having a sharp distal tip. The catheter and the introducer needle are assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from the patient""s skin.
The catheter and introducer needle assembly is inserted at a shallow angle through the patient""s skin into a peripheral blood vessel. These are smaller blood vessels that are not connected directly to the heart but are the branches of the central blood vessels that are directly connected to the heart. In order to verify proper placement of the assembly in the blood vessel, the clinician confirms that there is flashback of blood in the needle and in a flashback chamber located at the proximal end of the needle. The flashback chamber is typically formed as part of the needle hub. Once proper placement is confirmed, the clinician applies pressure to the blood vessel by pressing down on the patient""s skin over the distal tip of the introducer needle and the catheter. This finger pressure occludes further blood flow through the introducer needle. The clinician withdraws the introducer needle, leaving the catheter in place, and attaches a fluid-handling device to the catheter hub.
Once the introducer needle is withdrawn from the catheter, it is a xe2x80x9cblood contaminated sharpxe2x80x9d and must be properly handled. In recent years, there has been great concern over the contamination of clinicians with a patient""s blood and a recognition that xe2x80x9cblood contaminated sharpsxe2x80x9d must be immediately disposed. This concern has arisen because of the advent of currently incurable and fatal diseases, such as Acquired Immune Deficiency Syndrome (xe2x80x9cAIDSxe2x80x9d) and hepatitis, which can be transmitted by the exchange of body fluids from an infected person to another person. Thus, contact with the body fluid of an AIDS or hepatitis infected person must be avoided to prevent the transmission of such diseases to a healthy person. As noted above, if an introducer needle has been used to place a catheter in the vein of an AIDS or hepatitis infected person, the introducer needle is a vehicle for the transmission of the disease. Although clinicians are aware of the need to properly handle xe2x80x9cblood contaminated sharpsxe2x80x9d, unfortunately in certain medical environments, such as emergency situations or as a result of inattention or neglect, needlesticks with contaminated introducer needles still occur.
As a result of the problem of accidental needlesticks by xe2x80x9cblood contaminated sharpsxe2x80x9d, various needle shields have been developed. Generally, such needle shields work for their intended purpose but could be improved. For example, some needle shields are not positively connected to the introducer needle assembly and could be advanced distally past the distal end of the introducer needle. In addition, some introducer needle assemblies having a needle shield associated therewith are bulky, difficult to use or require special features or techniques to be operative or are ergonomically uncomfortable for the clinician to use.
It is therefore an object of this invention to provide an introducer needle assembly having a needle shield that is positively connected to the introducer needle assembly to prevent the needle shield from being advanced distally past the distal end of the introducer needle.
It is another object of this invention to provide an introducer needle assembly with a needle shield that is compact.
It is yet another object of this invention to provide an introducer needle assembly with a needle shield that is simple and easy to use.
It is still another object of this invention to provide an introducer needle assembly with a needle shield that requires no special features or technique to be operative.
It is a further object of this invention to provide an introducer needle assembly with a needle shield that is ergonomically comfortable for the clinician to use.
The catheter and introducer needle assembly of this invention includes a needle shield connected to the needle hub by a tether. The introducer needle has a sharp distal tip and a proximal end connected to the distal end of a needle hub. A flashback chamber is defined in the needle hub. A vented plug may be located in the open proximal end of the flashback chamber to allow air to escape from the flashback chamber when blood enters the flashback chamber from the introducer needle. The catheter, which has a distal end and a proximal end connected to the distal end of a catheter adapter, is coaxially disposed over the introducer needle so the sharp distal tip of the introducer needle is distal of the distal end of the catheter.
The needle shield is located substantially between the catheter and the needle hub and defines a longitudinally extending passage through which the introducer needle extends. The needle shield may include some barrier or other mechanism that prevents the sharp distal tip of the needle from being moved distally with respect to the needle shield after the sharp distal tip of the needle has been withdrawn into the needle shield. This prevents the sharp distal tip of the needle from being reexposed once it has been withdrawn into the needle shield.
The needle shield is connected to the needle hub by a tether that prevents the needle shield from being moved distally past the sharp distal tip of the needle once the needle has been proximally withdrawn into the needle shield. The combination of the barrier or other mechanism associated with the needle shield and the tether prevents distal movement of the needle with respect to the needle shield. This ensures that the sharp distal tip of the needle remains trapped in the needle shield after the needle has been withdrawn proximally into the needle shield after use.
The tether is folded over itself to form a plurality of pleats like an accordion. Each pleat or fold defines a central opening therein to allow the needle to extend through each pleat or fold no matter whether the tether is completely extended or completely folded with the needle shield adjacent to the needle hub. Each opening has a configuration where the radial dimension of the opening is smaller than the longitudinal dimension of the opening. For example, each opening can have a generally race track configuration, an elliptical configuration or a generally rectangular configuration. Because the tether can be folded into a small space so it is located between the needle shield and the needle hub, the overall device is compact. This makes the overall device easier to control by the clinician. In addition, the pleated configuration of the tether allows the clinician to better control the action of the needle shield. The tether is connected to the needle hub and the needle shield by a variety of mechanisms, such as by an adhesive, by heat-sealing or by mechanical engagement.